Data stored in database systems is often received from other computers, sometimes called client computers, that store the data for a different purpose or for different types of access. The client computer can store extraneous data intermixed with data to be included in the database system. Database systems often organize the stored data in a tables. For example, relational database management systems can be configured by tables. In a conventional process, data can be sent from the client computer to the database system without distinguishing extraneous data. The database system then determines which portions of the received data are needed for its tables and which portions are extraneous.
The portions of the data that are needed by a database system can depend upon the operation to be performed on the database system tables. For example, an insert operation, which adds a new row or record to a table of the database system, requires all the data to be included in that row. A delete operation, on the other hand, just needs enough data to identify the row or rows to be removed. An update operation requires data for the portions of the row or rows to be modified as well as data identifying the row or rows to be modified.
A conventional process for transferring data to a database system can include having a user specify particular data items that are to be transferred to the database system and other data items that are not. If a large number of records are involved and different records require different treatment, this may not be efficient.